A service control point (SCP) is a core of a mobile intelligent network in the present communication network, and is loaded with a service logic and user data. When a user of a mobile intelligent network initiates a call or is called, a mobile switching center or service switching point (MSC/SSP) reports a detect point (DP) message or an initial detect point (IDP) message to the SCP, thereby initiating a mobile intelligent service on the SCP, and a call process is controlled by the SCP. The SCP controls the call basically in such a way that after the call triggers the SCP, the SCP starts an intelligent service logic for performing basic call processing (e.g., obtaining a calling number and a called number through analyzing), inquires the user data for performing call authentication, analyzes validity of the user's account, if the call is determined to be valid, requires the MSC/SSP to continue the call, and performs accounting. Finally the control process in the SCP ends after a user of a terminal hangs up, and a call control is completed.
In the communication network, each access terminal has an identifier. For example, there is a number for accessing a global system for mobile communication (GSM) network, a public switched telephone network (PSTN), a code division multiple access (CDMA) network, and the like. The number is transferred to a called terminal by the communication network when a calling terminal initiates a call. A user of the called terminal may see the number of the calling terminal as long as he or she has launched a call ID display service.
Taking the GSM network as an example, the MSC sends a call request of the calling terminal to a network in which the called terminal is located when a call occurs. The network in which the called terminal is located sends a call with a calling terminal number to the called terminal. The called terminal decides whether to answer the call or not according to the received calling terminal number, or inquires user information of the calling terminal from user information phonebook it stores according to the received calling terminal number and decides whether to answer the call or not according to an inquiry result.
Currently, since the called terminal can only receive a string of digital signals and cannot carry more information, the calling terminal number can be identified solely on the called terminal. However, when the following situations occur, for example, 1), the called terminal has not been informed of the calling terminal number; 2), the terminal's phonebook cannot record information of all numbers due to a limited capacity (for example, there is thousands of persons in a consortium, but only one hundred to two hundred persons are recorded in the terminal's phonebook); and 3), the terminal's phonebook is lost due to loss of the terminal and so on, the terminal may not display enough user information, so that it is difficult for the user of the called terminal to determine whether to answer the call or not.
In reality, there are many situations that the user of the called terminal is willing to selectively answer the phone, for example, it is probable that he or she does not want to answer calls from telemarketers when attending a conference or carrying out an important work. Usually, people may remember a small number of telephone numbers, which are only some frequently-used numbers, and such few numbers cannot cope with an ever increasing communication requirement. Therefore, in many situations, the user of the called terminal may only answer the phone tentatively and then hang up quickly, but the ongoing work has already been disturbed.